y=1.3;
xn=0.1;
for n=1:1:1000
    xn1=1-(y*xn^2);
    xn=xn1;
end

for n=1:1:1000
    xn1=1-(y*xn^2);
    itog(n,1)=xn;
    itog(n,2)=xn1;
    xn=xn1;
    itog(n,3)=n;
end
plot(itog(:,3),itog(:,1),'r.');